Date post: | 13-May-2015 |
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Environment |
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Research Faecal Sludge Treatment
Background
Gap Analysis in Emergency Water, Sanitation and Hygiene Promotion (HIF 2013)1. Latrines in locations where no pits are possible
(urban, high watertable/flooding)2. Latrine emptying and desludging3. Faecal sludge disposal options after desludging
and treatment !!MOST CHALLENGING GAP!!4. Urban alternatives for excreta disposal
Problem
• Lack of space for treatment (urban area)• High water table (no digging possible)• No off site treatment/disposal site, no skilled
labour• Security• Faecal sludge source of disease (Cholera Haiti)• Raised latrine full after 1 week
Objective
• Sanitization Faecal Sludge• Simple & rapid & easy to put
in place• Easy to operate & maintain
& reliable• Demonstrate feasibility at
scale and document the whole process
• Process to be incorporated in the Oxfam and/or IFRC catalogue
• From Speed to Seed
Field testing Malawi
• 5 Students from Unesco-IHE & TUD
• 3 Treatment Methods for Centralised Treatment : – Lime, Ammonia, Lactic Acid
• 3 Decentralised Treatment (SEED)- on-going research: – Worm Toilet, Terra Preta
Toilet, Anaerobic Digester
Emergency Faecal Sludge Treatment Methods:
Preliminary Field Testing Results
Treatment
• Treatment Time
• Final Concentration of E-coli, Salmonella and Faecal Coliform
• pH
• Quantities of Chemical Addition for Treatment
Ammonia
• 4-8 days
• <1000 cfu/ 100ml
• pH 9
• 2% Urea w/w (20g urea/kg Sludge =9g TAN/kg Sludge)
Lime
• 2 hours
• <1000 CFU/ 100ml
• pH 11
• 12-16g Lime per kg Sludge ( The buffer capacity varied considerably between sludges)
Lactic Acid
• 7-9 days
• <1000 cfu/ 100ml
• pH 4
• 20-30 g/L Lactic acid concentration (using 10%w/w preculture, 2g simple sugar/kg sludge)
Lactic Acid Experiments
• 3 Log removal for E-coli 7-9 days
• 10% w/w milk preculture, 10% w/w molasses ( 2kg simple sugar/1000kg sludge)
• 20-30g/L lactic acid• pH: 3.8-4.2 • Next Phase –
knowledge applied to Terra Preta Toilet
UREA EXPERIMENTS
• 3 Log removal 4-8 days after addition of urea
• 2% Urea observed to be the most effective
• pH 9 – 9.5• Reactors must be sealed • High temperature can
enhance treatment• Next Phase – upscale to
Bladder
LIME EXPERIMENTS - MALAWI
• 50L Drum Experiments• pH Control - Addition of
Hydrated Lime ( CaOH) & 10’ mixing
• > pH 10.2 to <1000 CFU/100ml within 1 hour
• No distinct reduction in COD and TS or VS within
• Further research upscaling
ControlpH 7
pH 9 pH 10 pH 11 pH 12
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.51.00E+00
1.00E+01
1.00E+02
1.00E+03
1.00E+04
1.00E+05
1.00E+06
1.00E+07
E-coli RemovalControl ( no mix)
Control ( mixing
pH 9
pH 10,2
pH 11
pH 12
Time elapsed since Lime addition (hours)E-
coli
Conc
entr
ation
( CF
U/10
0ml)
Future Work
Additional Research is essential to ensure that a robust method which safeguards public health can be established for faecal sludge treatment in an emergency context
(De) Centralized:• Lime Treatment• Urea Treatment On site:• Self-mixing Anaerobic
Digester• Worm Toilet• Terra Preta Sanitation Toilet
.
Future work
(De-) centralized treatment:• Upscale options, test robustness of process on different
sludge types & in different settings• Investigate sanitization, stabilization, costs• Devise the process conditions required for Faecal Sludge
Treatment to achieve the WHO guideline sanitation requirements.
On-site systems:• Compare and contrast each of the on-site sanitation systems• Investigate the functionality of the on-site sanitation systems• Investigate sanitization, stabilization, costs, useful byproducts
Thank you for your input!
www.emergencysanitationproject.orgwww.speedkits.eu